VTS Mapproxy generates the requested data on the fly but to do it fast it needs the input data to be suitably preprocessed - e.g. raster data should have overviews, there has to be a way to quickly tell if there are some data for given place at all (tiling metainformation) etc..

Aka generate VRT With Overviews does the similar job to gdaladdo but is designed to efficiently handle large VRT datasets (worldwide DEMs, orthomosaics etc.). It is perfectly usable even for small
rasters but you can use gdaladdo there or use them straight away in case they already have appropriate overviews.

Note

For DEMs and DSMs three sets of overviews with different resampling algorithm are required so even simple DEM with overviews will require additional preprocessing.

Resampling method, one of dem, min, max and texture. texture is resampling suitable for textures (average for scales smaller than 0.5, cubic otherwise) and dem is suitable for terrain (average for scales smaller than 0.5, cubicspline otherwise)

tileSize

Specified as PIXELSxPIXELS, e.g. 1024x1024. Although the result of overview generation is an opaque VRT, each overview layer is physically split into tiles of specified size. This allows for work parallelization, shear ability to store the result in case of detailed world-wide datasets and for subtle optimizations like discarding all-sea tiles.

If whole warped tile contains this color it is left empty in the output. Solid dataset with this color is created and places as a first source for each band in all overviews, acting as a fallback for this empty space. Suitable for datasets with large water bodies.

co

GTiff extra create option; can be used multiple times. The default is DEFLATE compression.

nodata

Optional nodata value override. Can be NONE (to disable any nodata value) or a (real) number. Input dataset’s nodata value is used if not used.

Calculates recommended tile ranges and LOD ranges of given raster dataset for specified reference frame. It furthermore provides VTS position from which the dataset can be seen. These values are required in mapproxy resource definition.

Mapproxy tiling is the last step in raster preprocessing. It analyzes raster(s) with overviews and creates tiling metainformation telling which tiles are empty, partial or full (aka watertight). This information is needed (usually through metatiles) in various parts of VTS.

The tiling operation can be time consuming, especially for datasets with long data-nodata border in combination with high max LOD.

Path to directory with preprocessed raster. The directory must contain opthoto symlink to orthomosaic with overviews or dem, dem.min and dem.max symlinks to appropriate DEMs/DSMs with overviews. If no output parameter is set, the resulting tileindex file will be placed into the same directory. The directory may contain anything else, e.g. the resulting directories of generatevrtwo.